Fibreboard is conventionally produced by defibration or steam explosion of wood chips to obtain wood fibres, forming a mat of the fibres, and pressing the mat while applying heat and pressure. Conventionally, the mat is prepared either by a dry process from wood fibres with a water content below 120% (by weight of the dry fibres) with addition of adhesives, or by a wet process from an aqueous slurry of wood fibres with a water content of 200-10000% (by weight of the dry fibres).
In the wet process, it is conventional to add a binder (adhesive) to the aqueous fibre slurry and/or to cure the fibreboard at high temperature after the pressing, in order to improve the mechanical properties of the fibreboard.
SU 636,311 and DD 271,078 disclose processes wherein microorganisms productive of enzymes such as laccase are cultivated on wood chips before defibration to make wood fibres for use in fibreboard.
It is the object of this invention to provide an improved wet process for producing fibreboard of improved mechanical properties without the need for the addition of binder or the final curing.